优化

app/src/main/java/io/legado/app/help/storage/ImportOldData.kt

@@ -125,8 +125,8 @@ object ImportOldData {
             book.originName = jsonItem.readString("$.bookInfoBean.origin") ?: ""
             book.author = jsonItem.readString("$.bookInfoBean.author") ?: ""
             val local = if (book.origin == "loc_book") BookType.local else 0
-            book.type = local or
-                    if (jsonItem.readString("$.bookInfoBean.bookSourceType") == "AUDIO") BookType.audio else BookType.text
+            val isAudio = jsonItem.readString("$.bookInfoBean.bookSourceType") == "AUDIO"
+            book.type = local or if (isAudio) BookType.audio else BookType.text
             book.tocUrl = jsonItem.readString("$.bookInfoBean.chapterUrl") ?: book.bookUrl
             book.coverUrl = jsonItem.readString("$.bookInfoBean.coverUrl")
             book.customCoverUrl = jsonItem.readString("$.customCoverPath")